GEGL filter that makes Basic Pencil Drawings

contrast_ · **Joined:** Oct 31, 2020 **Posts:** 2013

Filter works best in Solid color backgrounds. It looks like crap if a lot of information is going on in the background.
https://github.com/LinuxBeaver/gegl-pen ... l-drawing/
@MareroQ will likely chime in with a Windows build port.

Pocholo · **Posted:** Sun May 15, 2022 9:51 pm **(#2)**

Good work, contrast_. I will like to create Gegl plugin, but I don't know how. Maybe you can post the basics?

MareroQ · **Posted:** Sun May 15, 2022 11:23 pm **(#3)**

Version for Gimp-2.10.30 Win 64 Bit attached.
Place the file in Gegl plugins in a directory: ... \lib\gegl-0.4\

In menu Tools➤GEGL Operation➤Pencil drawing

We have cli345 on the forum - a comic book style master and Gegl Graph expert - maybe he will suggest something or join this game?

contrast_ · **Joined:** Oct 31, 2020 **Posts:** 2013

Pocholo wrote:

Good work, contrast_. I will like to create Gegl plugin, but I don't know how. Maybe you can post the basics?

All I am doing is stitching more simple gegl operations together. look at my .c files on github and gegl.org and maybe you'll get the hang of it.

cli345 · **Posted:** Thu May 19, 2022 7:58 am **(#5)**

Hello,

Here is yet another pencil gegl graph:

Code: Select all

noise-reduction
domain-transform n-iterations=5
difference-of-gaussians radius1=1 radius2=0.33
gray
levels in-low=0.004 in-high=0.009
invert-gamma
rgb-clip
noise-reduction

Here are examples:

Attachment:

examples_orig.jpg [ 183.79 KiB | Viewed 6122 times ]

Attachment:

examples_geglPencil.jpg [ 153.6 KiB | Viewed 6122 times ]

Have fun!

contrast_ · **Joined:** Oct 31, 2020 **Posts:** 2013

cli345 wrote:

Hello,

Here is yet another pencil gegl graph:

Code: Select all

noise-reduction
domain-transform n-iterations=5
difference-of-gaussians radius1=1 radius2=0.33
gray
levels in-low=0.004 in-high=0.009
invert-gamma
rgb-clip
noise-reduction

Here are examples:

Attachment:

examples_orig.jpg

Attachment:

examples_geglPencil.jpg

Have fun!

I can try to make this into a filter and give you full credit for discovering the algorithm.

levels
domain transform
and difference of gaussian

will have sliders. Everything else will be hidden.

contrast_ · **Joined:** Oct 31, 2020 **Posts:** 2013

I make a filter that uses your algorithm and it will replace my gegl:pencil

This works on images even with complex backgrounds so i will have to change the description

contrast_ · **Joined:** Oct 31, 2020 **Posts:** 2013

https://github.com/LinuxBeaver/gegl-pen ... il-drawing

gegl:pencil has had a major overhaul. cli345 gets the credit. This algorithm unlike mine works in noisy backgrounds

MareroQ will have to recompile for Windows. lol

MareroQ · **Posted:** Thu May 19, 2022 11:20 am **(#9)**

New version for Gimp-2.10.30 Win 64 Bit attached.
Nice collaboration :bigthup

PixLab · **Posted:** Mon Aug 15, 2022 5:15 am **(#10)**

I'm quite impressed by this GEGL drawing filter, comparing with G'MIC (sketch or pencil filters), this GEGL is a winner for me (even though I don't use those type of filters).

I got few problem, tough, but the filter still work once I closed the GIMP window's bug

contrast_ · **Joined:** Oct 31, 2020 **Posts:** 2013

I will be removing the remove color mode from GEGL:photo2cartoon because this filter literally does that but better.

I don't want to fuse the two filters as gegl:pencil is much faster loading then gegl:photo2cartoon.

contrast_ · **Joined:** Oct 31, 2020 **Posts:** 2013